Dual 12" Subwoofers in '07 yaris

[sqcomp]

??"laws of physics do not work in some cars"?? Seriously?

Current draw is a vital link to Ohms law. Of course you don't care... it's because you're mistaken.

-Read the signature-

Question to all, not just our esoteric sage, what happens when the alternator can't put out more than it's rated output? This will lead to the answer...

[TOLMACH]

Originally Posted by sqcomp

??"laws of physics do not work in some cars"?? Seriously?

Current draw is a vital link to Ohms law. Of course you don't care... it's because you're mistaken.

-Read the signature-

Question to all, not just our esoteric sage, what happens when the alternator can't put out more than it's rated output? This will lead to the answer...

Interesting topic.. I do not know what happens to alternator

Questions to you:

1. How much electricity (in watts) do you need to supply to your DD amp to get 1200 wats at amp's speaker outputs?

2. What is your alternators's output (in amperes) at 3000 RPM ?

SPL guys use stacks of optima batteries to obtain the necessary short term current, which we ignore as this is not the case.. What other variables am I missing to achieve these notorious 1200watts?

[TOLMACH]

Updated calculations re Q1 above:
Producer seems to advise the electrical efficiency of 65%

http://www.ddaudio.com/products/mobi...eries/s2b.aspx

1200 W/ 0.65 = 1846 watts
1846 watts / 14 volts = 132 amperes that are need to get 1200 W

So, what do we do to get our 1200 watts?

[sqcomp]

SPL guys use batteries...

Your're getting warm brilliant one.

Now pour through my posts and figure out what kind of batteries I'm using. Now, answer the question. What happens when the alternator can't put out any more current?

Yes, I can put out 1200 Watts.

[mazilla]

...meanwhile, the OP is like "WTF is going on in my thread?"

[sqcomp]

Truth...We got off on a tangent regarding where current comes from.

This could go a lot further into the rabbit hole as well. There are quite a lot of variables into maximum output of amplifiers that we haven't talked about.

Oh, here's the answer:

"As long as the engine is running, all of the power for the accessories is delivered by the alternator. The battery is actually a load on the charging system. The only time that the battery would supply power with the engine running is when the current capacity of the alternator is exceeded or when engine is at a very low idle. "

Tolms still tearing through posts looking for what kind of batteries I use...

I'll save him the trouble:



That's been updated actually. I'm no longer using the secondary battery. The primary sits at a hair over 12.8 Volts and charges from the alty at anywhere from 13.9 to 14.3 Volts depending on the temperature.

Description:

◦SPP1200 includes removable brass battery posts for installation flexibility.
◦12v Dry Cell Valve Regulated Lead Acid Battery (AGM)
◦SPP Series Batteries are good for over 400 full discharge cycles.
◦Internal resistance: <4.0 mOhms = Ability to quickly deliver power. The lower the number the faster the delivery.
◦20 hour rate: 2.20A/44Ah
◦5 hour rate: 7.48A/37.4Ah
◦1/2 hour rate:55A/27.5Ah
◦5 Second Cranking Amps: 1200A
◦CCA: 560A
◦Watts: 2400
◦Peak Discharge: >2600 A

[vten]

im learning as well.... so u don't really need to replace the stock alternator to hook up more let say 1000W rms total ? as long as you use that stinger battery ?

by the way that L1 Pro SE is sexay !!!

[why?]

Originally Posted by vten

im learning as well.... so u don't really need to replace the stock alternator to hook up more let say 1000W rms total ? as long as you use that stinger battery ?

by the way that L1 Pro SE is sexay !!!

I am almost 100% sure SqComp is running an aftermarket or rewound alternator.

[TOLMACH]

Originally Posted by vten

im learning as well.... so u don't really need to replace the stock alternator to hook up more let say 1000W rms total ? as long as you use that stinger battery ?

by the way that L1 Pro SE is sexay !!!

replacing alternator is a must in case you need high total rms .. comp is merely trying to show that he can get his 1200 watts for like 45 seconds

[why?]

Originally Posted by TOLMACH

replacing alternator is a must in case you need high total rms .. comp is merely trying to show that he can get his 1200 watts for like 45 seconds

not 45 seconds... 1200 watts isn't even a lot. Two alpine type X's take 2000, and there are single subs that can take more. You can run them all day long with the right setup.

It is only when you get to insane SPL levels that you are talking about running the system for short periods of time.Like this. Totally insane.

[12 yaris]

WHAT? I can't hear anything

[12 yaris]

What? I can't hear anything.
I'm buying stock in Beltone!

[why?]

i here a few thousand watts in subs gives a real nice massage during the drive.

[sickpuppy1]

As I recall, SQ does have an aftermarket alternator. In case you havent noticed, he does not do stuff halfway. He learns,plans and executes. He's not here to brag, but to pass on knoweldge. Yes, I have alot of respect, but its based on a few years of reading here and audio forums.

[sqcomp]

The truth of it all is that most of us are only drawing tons of current for very short intervals. I can tell you this much, on our stock alty, the only time I would get dimming was when I had a bass track in and was railing on the volume.

Watching my Voltage readout like a hawk, I'd see the Voltage drop down to something like lower 12's. That bothers me. The current would still be supplied BUT... This is why one would buy an aftermarket alternator.

IIRC, 1200 Watts is almost irrelevant. Mos of our listening is done within the 10 Watt output range. Why do I use monster surfboard amps? A throwback to the 90's and the transient power capabilities. Think of the Top Gear analogy of racing a Prius versus an M3. The Prius (A smaller A/B amp) is efficient but a racing speeds is failed the whole time...whereas the M3 (a big A/B amp) is less efficient but doesn't even break a sweat at the Prius pace around the track. It has more to easily give.

Just my thoughts.

[sqcomp]

@ Why - info have some video of a near 160 dB street car..."massage"? It was more like a continuous donkey kick!

[why?]

Originally Posted by sqcomp

@ Why - info have some video of a near 160 dB street car..."massage"? It was more like a continuous donkey kick!

lol, i bet it would be. My best friend when i was in high school listened to gansta rap. At differing points he had 2 or 3 12's, 4 10's, and I think he even had a 15' or two at one point. I highly doubt he ever got anywhere near 160 db's, but he used to drive my sister to school and she always said it was a good massage. He also had a fetish for Phoenix Gold amps.

[sqcomp]

This one was a Kia Spectra hatch with ten vented 10" woofers...two altys and Tolm's favorite, a bank of batteries.